Step 2

Combine the dark chocolate chips, heavy cream and half the condensed milk in a microwave-safe bowl. Microwave in 20-second intervals, stirring between each, until melted and smooth. Stir in the vanilla extract.

Step 3

Spread the dark chocolate mixture evenly in the prepared pan.

Step 4

Combine the white chocolate chips and remaining half of condensed milk in a separate bowl. Microwave in 20-second intervals, stirring between each, until melted and smooth.

Step 5

Spread the white chocolate mixture evenly over the dark chocolate layer. Press the miniature marshmallows on top.

Step 6

Refrigerate for at least 4 hours until set. Lift out using the paper or foil, peel it away and cut into bite-sized pieces.